If we take a front view of the skull of an aged male gorilla we see that the upper edges of the great supra-orbital arches are bevelled off below and at the sides. This bevelled form is repeated in the broad cheek-bones, as we see them in front. The front view of the head, and indeed of the whole animal, presents a strongly projecting contour, an impression which is strengthened by the puffed cheeks, with their lateral pads of fat. The lower jaw, with its scarcely indicated chin, retreats in the centre and dwindles into a triangular form. This contour is characteristic of the species. The whole skin of the face is glossy, set with few hairs, and of a deep black colour. [Illustration: Fig. 2.--Ear of a male adult gorilla.] The ear (Fig. 2) averages 60 mm. in length, and from 36 to 40 mm. in width. It seems to be fastened to the head by the back and upper part, is generally of an oval shape, and furnished with a strongly marked helix. The helix varies in width in different individuals, and often terminates on its inner edge in the projecting peaked excrescence described by Darwin, of which I shall have more to say presently. The anti-helix, tragus, and anti-tragus, and the cleft which lies between these two latter parts (_incisura inter tragica_) are generally fully developed; the lobule is more rarely present. Individual variations in the special structure of these parts may frequently be observed. The strong trapezoid muscles are prominent on the neck, and when the head is stretched they stand out like pillars on the sides of the neck. Owing to the great development of the spinous processes of the cervical vertebræ and of the muscles attached to them, and to the occipital bones of the skull, the neck is very powerful, almost like that of a bull. The shoulders are remarkable for their breadth, and the pectoral muscles for their large size. The nipples of the breast, which are not surrounded by any visible _areolæ_, stand out in youth, and afterwards assume a horny texture which stiffens into a kind of bone. When one of these animals is gorged with food the navel is still apparent on the tun-shaped, rounded belly, of which the sides fall in when the stomach is empty.